M3A78-PRO and voltage problems

[AndreaACME]

I own an ASUS M3A78-PRO (780G/SB700) Mobo which is great to play with for OCing but it has many limitations on voltage regulations. I'm currently running on the latest BIOS (v1404) and I have two catastrophic limitations:

(1) CPU volts [up to 1.3V]
(2) RAM volts [from 1.9 to 2.3V]

About point (1):
My CPU (AMD 940BE is rated for 1.35V for normal operation, so from BIOS if I choose manual setting I can only underclock and not even get to par!! Measuring with CPU-Z and AMD Overdrive I actually always read 0.025V less than what is set in the BIOS but that is a fixed offset so I just take it into consideration and always add 0.025V to what I want to set. If I use AMD OD to push the volts up then it raises at will.
Is there a way I can "unlock" the BIOS to go higher than 1.3V? Have I got something wrong here? What's up with my BIOS/Mobo? Any ideas?

About point (2):
If on BIOS I set my RAM to manual 1.9V, or any other value for that matter, I get an AMD OD reading of 1.8V. Another strange thing is if I set the lowest value on AMD OD (0.8V) my system is still happy and stable; which probably mean that I have no control over RAM voltage. This is hindering my overclocks badly! If I set the RAM to 1066MHz I can't even boot probably because of the low voltage (1.8V standard).


Any ideas?


-----------------------------------------------------
[CPU] Phenom II 940BE 3GHz
[RAM] Corsair 8GB 4*2GB DDR2-1066 Dominator 8500C5D 5-5-5-15
[Mobo] ASUS M3A78-PRO
[GFX] nVidia GTX285 1GB DDR3
[PSU] Corsair TX850W APFC
-----------------------------------------------------
Component overclocking abilities (stable Prime@30min):
[stock cooking and C&Q disabled]
FSB [200 - 270]MHz
CPU [3000 - 3350][email protected]
RAM [400 - 447][email protected]
NB/HT [1800 - 2200][email protected]

 

[Yellowbeard XMS]

If you have access to a volt meter, I'd suggest you find the points on the motherboard and test these values with a meter. If you verify them to be bad or incorrect, I'd contact ASUS.

 

[AndreaACME]

I have a voltmeter but where would I go testing it? Which voltage controller should I measure? Is there a "manual" or accurate way of determining which one is for the RAM? There are at least 5 of them sitting below the DIMM sockets.

And what about the CPU voltage limit? Can anything be done with that? I know the voltage is working there because if I undervolt it it simply doesn't boot and the higher I push it, the higher OC I can get on it.


Thanks.

 

[QuietIce]

Do you have AI Overclocking set to manual? (just checking )

Have you tried a hard reset of the BIOS since you updated? Change the jumpers, take the battery out for an hour, then re-install the battery and switch the jumper back. If that doesn't work try removing a RAM stick, restart the computer, shut down, then re-install the RAM stick. Usually one of those two methods (or both together) will cause the BIOS to do a complete reset & re-read of hardware ...

 

[AndreaACME]

Do you have AI Overclocking set to manual? (just checking )

Have you tried a hard reset of the BIOS since you updated? Change the jumpers, take the battery out for an hour, then re-install the battery and switch the jumper back. If that doesn't work try removing a RAM stick, restart the computer, shut down, then re-install the RAM stick. Usually one of those two methods (or both together) will cause the BIOS to do a complete reset & re-read of hardware ...

Wow, very complex procedures you have there

Anyway, YES I am in manual settings even now that I'm not overclocking. Obviously from the BIOS the lowest voltage I can set for RAM is 1.9V (and that is above RAM specs anyway [1.8V 800MHz -2.1V 1066MHz])

Anyhow today I have a voltmeter so when I get back home I'm going to be probing every voltage regulator of my Mobo. I'll let you know.

I will try a hard reset of the BIOS before giving up though

 

[AndreaACME]

Back again ... I have 1 good news and 1 bad news.

First the good one: my RAM can be voltage controlled from the BIOS, actually that is a "ONLY from the BIOS". The available voltages are actually from 1.9V to 2.25V (in increments of 0.05V) and in AUTO it is normally set to 1.9V.
Aparently ASUS don't use a sensor for the RAM voltage so it can't be read nor set from software, only the BIOS can regulate it once at startup.

I went with a multimeter and found out, out of the 9 voltage regulators on my Mobo, which one feeds the current into the RAM and below are the test results with 4GB installed (2 sticks) and 8GB installed (4 sticks):

BIOS    w/4GB    w/8GB
-----   ------   ------
1.90V   1.909v   1.911v
2.10V   2.085v   2.087v
2.15V   2.131v   2.134v
AUTO    1.909v   1.911v

Now for the bad news: I tried flushing (jumper hard reset) the CMOS RTC to no avail and the only effect was to reset all my RAID settings, the date and the various options in my Mobo. My CPU voltage limit is still 1.3V

I don't believe ASUS can stay on their butt with such a problem out since BIOS version 0904 !!! I've tried flushing into all the older versions just to make sure that this limit wasn't implemented only on recent versions. I can't go beyond v0904 otherwise my PhenomII will not be recognised and I will not be able to bootstrap the BIOS.


Any ideas are welcome.

 

[QuietIce]

If the hard reset and taking out a RAM stick didn't work then I'm out of ideas ...

 

[AndreaACME]

I went with 4GB (2 sticks) and then back to 8GB (4 sticks), I think that changed things enough? ...
Or did you want to create an odd measure for RAM, like say: 6GB or 2GB ? As in trying to go single channel and not use dual channel?

 

[QuietIce]

It's the single/dual memory channel thing that resets the BIOS. By closing the option for dual channel the BIOS is forced to re-read the hardware (I'm don't know how that works either). This little trick was quite useful back when dual-core CPUs first came out. Many people had been running single-core but when they dropped in a dual-core the BIOS sometimes failed to pick up the change in CPUs. By switching the RAM to single channel it often forced a re-read of the hardware, which would also pick up the change in CPU from single- to dual-core. Not sure it would work the same with modern BIOS' or not but it's relatively easy to do so I always suggest it in cases like yours as a last resort ...

 

[AndreaACME]

Ok, I will try that single channel and see how it goes although I really think it is a limitation of my MoBo.

Do you know if for my MoBo (as I have read for others) there is a secret combination of keys to unlock more options once you're in the BIOS?


P.S. Just to close the discussion on point (2), I found the problem that was giving me random reboot failures. The random booting was due to one of the last timing values set wrong (tRFC4=75us too tight), it was in the last lines of my BIOS which you have to scroll down to be able to see.

 

[QuietIce]

As far as I know ASUS doesn't hide BIOS settings like that - though some companies do or have in the past.


Ya', for 4 sticks or very fast RAM speeds 75us is probably a little fast. Glad you found that ...

 

[AndreaACME]

As far as I know ASUS doesn't hide BIOS settings like that - though some companies do or have in the past.


Ya', for 4 sticks or very fast RAM speeds 75us is probably a little fast. Glad you found that ...

Found another interesting thing about my MoBo: the voltages I set in the BIOS (or AOD for that matter) are slightly higher in reality (@IDLE) to compensate for voltage droop and actually drop down to the set value when under load. As to say: setting 1.3v in the BIOS would yield 1.320v@IDLE and will drop down to 1.300v@LOAD. This was veified with a voltmeter and is true for all tested voltages (from 0.850v up to 1.450v stepping 0.05v) !!
I also checked the temperatures on the voltage regulators while under load and they are just fine (with no heatsink).

Everytime I look into a new feature/problem of my MoBo, I find something amazing about it that makes me realise it is not such a bad product after all. At first I was really dissapointed about its limitations but as I learned they can be overcome somehow.

 

[enty84]

This is the solution.

Afudos 2.19: ftp://ftp.asus.com.tw/pub/ASUS/mb/flash/AFUDOS219.zip

Bios Mod: http://www.megaupload.com/?d=9ZTXGYNZ


USB disk boot: http://rapidshare.com/files/51276853/Crear_USB_Booteable.rar
Steps: Install HP program. Create bootable USB with DOS files.

Rename the bios with an easier name to avoid typing errors.

Enter AFUDOS.EXE and Bios Mod within the USB bootable.

Restart PC, press F8 and select boot from USB Disk.

Write: afudos /iBiosMod.rom

command (/i) is to flash.

If all goes well you reboot, you enter the BIOS setup, you do a reset and come back. When you're in the area of voltage, you can see that you can increase the CPU voltage to 1.60V easily.

I hope you like this post. I personally find a lot infirmacion costs relating to this board. Greetings.

 

[Virginio]

the link to download the mod bios doesn't work

This is the solution.

Afudos 2.19: ftp://ftp.asus.com.tw/pub/ASUS/mb/flash/AFUDOS219.zip

Bios Mod: http://www.megaupload.com/?d=9ZTXGYNZ


USB disk boot: http://rapidshare.com/files/51276853/Crear_USB_Booteable.rar
Steps: Install HP program. Create bootable USB with DOS files.

Rename the bios with an easier name to avoid typing errors.

Enter AFUDOS.EXE and Bios Mod within the USB bootable.

Restart PC, press F8 and select boot from USB Disk.

Write: afudos /iBiosMod.rom

command (/i) is to flash.

If all goes well you reboot, you enter the BIOS setup, you do a reset and come back. When you're in the area of voltage, you can see that you can increase the CPU voltage to 1.60V easily.

I hope you like this post. I personally find a lot infirmacion costs relating to this board. Greetings.

the link to download the mod bios doesn't work, please i need to un unlock the voltage....

 

[RGone]

Closing in on 4 years since the last post was made in the thread and I doubt that link would work. I even think Megaupload has changed hands. i doubt you find any of those guys in original thread still hanging around. Or you might just be lucky.
RGone...

 

[Virginio]

Closing in on 4 years since the last post was made in the thread and I doubt that link would work. I even think Megaupload has changed hands. i doubt you find any of those guys in original thread still hanging around. Or you might just be lucky.
RGone...

thanks for reply, i will try.

 

[RGone]

I just like to look for things...

...so I did some more searching. That bios you are looking for came from Asus Tech support as a Beta bios and was bugged to hale and back by the response of most who got to use it in 2009. Even with that Beta thing the board still set a Vcore value less than the advertised 1.7Volts. The most that anyone got was 1.5 Setting in bios that produced only a real 1.424Volts to the cpu.

You would likely be better served to move on to another board/platform since that was the only bios I ever saw anyone say helped even a little and I did not find that old beta release anywhere.
RGone...